Page 81 - PortGPT_V2.1_C8_Flipbook
P. 81

The if Statement

                 The if statement is the simplest conditional statement. Here, a statement or a collection of statements
                 within the if block is executed only if a certain condition or expression evaluates to True. If the
                 condition evaluates to False, then the control of execution is passed to the next statement after the
                 if block. The syntax of the if statement is given below:

                 Syntax:

                 if (condition)                                                                              False
                                                                                         Test Expression
                 {

                       // When the condition is true then block of                               True
                     code to be executed.
                 }                                                                          Body of if



                                       Tech Fact
                    In JavaScript, the non-zero value is interpreted as               Statement just below if
                            true and 0 are interpreted as false.





                  Program 1: To check whether a given number is positive.


                 <!DOCTYPE HTML>

                 <HTML>
                 <HEAD>
                     <TITLE> if statement </TITLE>
                 </HEAD>

                 <BODY>
                 <SCRIPT>
                     var num = parseInt(prompt("Enter the number: "));
                     if(num > 0)

                     {
                       document.write("Entered Number is Positive");
                     }
                 </SCRIPT>

                 </BODY>
                 </HTML>










                                                                                 Conditional Statements in JavaScript  79
   76   77   78   79   80   81   82   83   84   85   86